/Engine/Plugins/Media/PixelStreaming/Source/PixelStreaming/Public/IPixelStreamingStreamer.h
Set the Target Viewport for this streamer. This is used to ensure input between the browser and application scales correctly.
void SetTargetViewport ( [TWeakPtr](API\Runtime\Core\Templates\TWeakPtr)< [SViewport](API\Runtime\Slate\Widgets\SViewport) > InTargetViewport )